#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	
	int c = 0;
	
	int b = 0;
	for (b = 1; b < 100; b++)
	{
		if (b % 10 == 9) c++;
		else if(b / 10 == 9 && b % 10 != 10) c ++;
	}
	printf("%d", c);
	return 0;
}